1. Field of the Invention
The present invention relates to winch systems (see DEFINITIONS section) and more particularly to winch systems designed for use with a load that: (i) consumes electrical power (for example, a lamp) and/or (ii) utilizes a control signal (for example, an display screen that displays a display corresponding to a fiber optic video data signal).
2. Description of the Related Art
Conventional lift systems include a force cable, a drum and a load. One end of the force cable is wound around the drum and the other end extends away from the drum, often through pulleys, to a point where it is attached to the load so that the force cable transmits mechanical force to the load. The drum is rotated to wind and unwind the lift cable and thereby move the load. As a simple example, in hand cranked theatre winches the force cable was generally a rope.
Other conventional lifts are electrically powered, such as lifts including an electrical motor. One example of this kind of lift is found in U.S. Pat. No. 2,942,879 (“Izenour”), which discloses a lift system including a motor, a drum, a line and a scenery unit. In the Izenour system, the line is the force cable and the scenery unit is the load. In the Izenour system, the motor powers rotation of the drum to wind and unwind the line, and thereby lift and lower scenery units. Although electrical power is supplied to the motor in Izenour, so that the motor can operate to rotate the drum, no electrical power is supplied to the force cable itself in the Izenour system.
It is conventional for the loads supported, raised and lowered by conventional lift systems to include components that require and consume electrical power. For winch systems that move loads which require electrical power, a separate power cable is conventionally provided. The separate power cable runs from a power supply (for example an electrical utility power outlet) to a power input on the load. Electrical current runs through the power cable from the source to the load and provides electrical power to the load. However the power cable must be able to accommodate the motion of the load caused by the winch system. For example, U.S. Pat. No. 5,570,546 (“Butterworth”) discloses a system for raising and lowering telecommunications equipment along a mast pole. The Butterworth system includes lift cables and coaxial signal cables. The lift cables and coaxial signal cables are separate from each other. As will now be discussed, there are several different conventional ways that separate power cables are applied to loads that are moved by winch systems.
The simplest way is called “loose cables,” which means that a large length of slack and relatively unconstrained power cable is maintained between the power source and the load. As the load is moved by the winch system, the load will pull an end of the power cable and take up some of the slack. The slack cable may be placed out of the way manually on an ongoing basis to try to ensure that the cable does not: (i) get tangled with people or objects; (ii) does not get caught in moving mechanical equipment; and/or (iii) does not move into an unsightly or view-obstructing position. Although the loose power cable solution does not require any extra equipment, beyond perhaps some extra length of power cable, the challenge of keeping the cables out of the way is burdensome and may even lead to risks of equipment damage or even personal injury.
Some conventional kinds of equipment for handling separate power cables for winch loads include: (i) cable reels; (ii) windlasses; (iii) folding cable trays; (iv) cable baskets; and/or (v) coiling cones. It is believed that these kinds of equipment, and their associated separate power cable handling methods, are and remain in wide use because they perceived by those of ordinary skill to be adequate, effective, cost-effective and optimal solutions to the problem of getting electrical current to a winch load for most winch system applications. For example, U.S. Pat. No. 5,556,195 (“Glebe”) discloses a motorized electrical apparatus for movement of an electrical fixture. The Glebe apparatus includes a retractable cable reel assembly for handling a separate power cable.
U.S. Pat. No. 7,153,001 (“Kim”), in describing a certain publication, states the following: “As shown in another related art, i.e., Korean Utility Model Application No. 20-2002-0033396, the wire combination structure of the said lift lighting system comprises a wire 304 having a rope 301, a grounding wire 302 and electric power supply wires 303 in an outer cover 300; a winding reel 306 on which the wire 304, at the end of which the lamp is installed, is rolled, and on one side of which pulleys 305 and 308 is installed; a power supply part 307 in which the pulley 305 is installed on the shaft of the motor 312 to operate the winding reel 306; belt 309 connecting the pulley 305 of the power supply part with the pulley 308 of the winding reel; a bracket 311 fixing the winding reel 306 to the frame 310. In the wire combination structure of the said conventional art, because the rope 301, the grounding wire 302 and the electric power supply wires 303 are combined in one wire, there can be a fall of the lamp owing to the rotation or twist of the lamp itself or the weight of the lamp.” (Reference numbers refer to FIGS. 1 to 3 of this document which have been drawn to match FIGS. 1 to 3 of the Kim patent.)
The Kim patent goes on to comment about the disclosure of the preceding paragraph as follows: “In the wire combination structure of the said conventional art, because the rope 301, the grounding wire 302 and the electric power supply wires 303 are combined in one wire, there can be a fall of the lamp owing to the rotation or twist of the lamp itself or the weight of the lamp. In addition, because the width of the winding reel on which a wire is rolled is wide, in case the wire is not rolled regularly on the horizontal direction but is twisted doubly or triply, the lamp itself can be rotated or twisted. And in case that the lamp is lifted up and down by two wires to solve the said problem, the balance of the lamp cannot be kept due to the winding error and the difference of the winding speed.”
Electric commutators are conventional. Fiber optic data signal commutators are conventional. Rotary seals in fluid supply lines are conventional.
Description of the Related Art Section Disclaimer: To the extent that specific publications are discussed above in this Description of the Related Art Section, these discussions should not be taken as an admission that the discussed publications (for example, published patents) are prior art for patent law purposes. For example, some or all of the discussed publications may not be sufficiently early in time, may not reflect subject matter developed early enough in time and/or may not be sufficiently enabling so as to amount to prior art for patent law purposes. To the extent that specific publications are discussed above in this Description of the Related Art Section, they are all hereby incorporated by reference into this document in their respective entirety(ies).